First you need to figure out if you have a deadlock or lock timeout. Reason code 2 is a deadlock, and 68 is a lock timeout. If you are getting lock timeouts, check the locktimeout database parameter (check the Administration Guide: Performance for details).
Normally, one would not have a locking problem with select statements only. You might want to check the autocommit option to make sure it is being used. Also, adding commits to your scripts could help in some situations.
If you are running certain utilities from the command center, then lock contention could be a problem if the utility needs an exclusive use of the table.